This invention relates generally to a pump and motor assembly which is utilized to regulate the flow of fuel to an engine.
It has been suggested that it would be desirable to provide a fuel distribution system in which a pump is driven by an electric motor having a speed which is controlled in accordance with one or more parameters in a manner similar to that disclosed in U.S. Pat. Nos. 2,687,123; 3,036,564; 3,236,221; 3,470,854; 3,470,858; 3,643,635; 3,817,225; and 3,935,851. If varying the speed of the electric motor is to be effective to provide a desired variation in fuel flow, it is necessary for the fuel discharged from the pump to be free of air. Of course, if vapor bubbles are entrained in the fuel, the rate at which fuel and vapor bubbles discharged from the pump will not provide an accurate measure of the amount of fuel being transmitted to the engine. In addition, it is desirable to avoid pressure peaks which result in irregular fuel flow during operation of the electric motor and fuel pump.
It is desirable to mount the fuel pump and its electric drive motor in close proximity to the engine. This involves locating the pump and motor in extremely cramped quarters. When the pump and motor are to be mounted at such a location, the making of fluid tight connections with the pump is relatively difficult. Yet it is extremely important that these connections be fluid tight since the leakage of fuel onto a hot engine could result in serious problems.